Question

Calculate the energy (in eV) required to heat one molecule of oxygen vapor by 100oC.

Answer 1

Solution :-

Specific heat of the oxygen is 0.919 J / g C

so lets calculate the amount of energy needed to heat 32 g O2 = 1 mol

q= m*c*delta T

= 32 g *0.919 J per g C * 100 C

= 2941 J

now lets convert this energy for 1 molecule

2941 J * 1 molecule / 6.02*10^23 molecules = 4.885*10^-21 J

now lets convert the joules to eV

4.885*10^-21 J/molecule * 1 eV / 1.602*10^-19 J = 3.049*10^-2 eV

So the amount of eneergy needed to heat one molecule of oxygen vapor is 3.049*10^-2 eV